A traffic roundabout (also termed traffic circle or rotary) is a central island located at the intersection of several vehicle roadways around which vehicles entering from the roadways flow in a circular pattern. Roundabouts offer several benefits to traffic flow. Traffic congestion can be reduced compared to all-way-stop-sign and traffic light-controlled intersections. The speed of approaching vehicles can be reduced at stop-controlled intersections, providing gaps for entry of minor-road traffic.
Miniature roundabouts (mini-roundabouts) are characterized by a small diameter central circle with traversable central and splitter islands. Mini-roundabouts can double traffic-handling capacity compared to 4-way stop sign control. They can cost less than larger roundabouts by eliminating land purchase or utility/drainage relocation. Mini-roundabouts can result in greater safety for drivers, pedestrians, and bicyclists. They offer most of the benefits of larger diameter, non-traversable roundabouts with the added advantages of smaller footprint and lower cost, making them attractive improvements for many two-and three-lane intersections.